1.It is Chinese size, the size is smaller than Euro Size, please take one size larger than your usual size.2.We have size chart, you can choose your size according to your feet length, For slippers, if you want it to be loose, you can choose a big one size, it is also very comfortable.Foot length 22.5-23(cm) Choose Size 36-37Foot length 23.5-24(cm) Choose Size 38-39Foot length 24.5-25(cm) Choose Size 40-41Foot length 25.5-26(cm) Choose Size 42-43Foot length 26.5-27(cm) Choose Size 44-453.Please choose 1-2 size bigger if your feet run wide or fat4.You can freely contact with us if you need any help!